Nasolacrimal duct obstruction can also cause lacrimal overflow. Common causes of obstruction are abnormal lacrimal duct position and lacrimal duct occlusion or narrowing due to blepharitis, trauma, congenital lacrimal duct occlusion or eyelash insertion into the lacrimal duct, in addition to lacrimal duct obstruction or narrowing due to trauma, inflammation, trachoma, streptococcal infection, etc. Other major causes of tear overflow include: 1, tear dots abnormalities: tear dots ectropion, narrowing, occlusion or no tear dots, tears can not flow into the tear duct. 2, tear duct abnormalities: developmental abnormalities (congenital atresia), trauma, foreign bodies, inflammation, tumors, scar contraction or nasal disorders, such as narrowing or obstruction of the tear duct, can occur tear overflow. Tear overflow is diagnosed as cold tear syndrome in Chinese medicine. Mostly due to liver and kidney weakness, Qi and blood deficiency, can not constrain the tears and tears often flow. Long-term tear overflow, the skin near the inner canthus is flushed and rough, eczema occurs, and the lower lid can be prompted to turn outward because the patient keeps wiping downward. The main reason for the existence and development of tear overflow disease is the smoothness of the tear duct, as long as there is a tear duct obstruction, the chronic inflammation still exists, so go to a specialist in time when you find a tear overflow situation.